The Short-Chain Alcohol Dehydrogenase ABA2 Catalyzes the Conversion of Xanthoxin to Abscisic Aldehyde[W]
Author:
González-Guzmán Miguel1, Apostolova Nadezda1, Bellés José M.1, Barrero José M.2, Piqueras Pedro2, Ponce María R.2, Micol José L.2, Serrano Ramón1, Rodríguez Pedro L.1
Affiliation:
1. Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia–Consejo Superior de Investigaciones Científicas, Camino de Vera, E-46022 Valencia, Spain 2. División de Genética e Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, E-03202 Elche (Alicante), Spain
Abstract
AbstractMutants able to germinate and perform early growth in medium containing a high NaCl concentration were identified during the course of two independent screenings and named salt resistant (sre) and salobreño (sañ). The sre and sañ mutants also were able to germinate in high-osmoticum medium, indicating that they are osmotolerant in a germination assay. Complementation analyses revealed that sre1-1, sre1-2, sañ3-1, and sañ3-2 were alleles of the abscisic acid (ABA) biosynthesis ABA2 gene. A map-based cloning strategy allowed the identification of the ABA2 gene and molecular characterization of four new aba2 alleles. The ABA2 gene product belongs to the family of short-chain dehydrogenases/reductases, which are known to be NAD- or NADP-dependent oxidoreductases. Recombinant ABA2 protein produced in Escherichia coli exhibits a K m value for xanthoxin of 19 μM and catalyzes in a NAD-dependent manner the conversion of xanthoxin to abscisic aldehyde, as determined by HPLC–mass spectrometry. The ABA2 mRNA is expressed constitutively in all plant organs examined and is not upregulated in response to osmotic stress. The results of this work are discussed in the context of previous genetic and biochemical evidence regarding ABA biosynthesis, confirming the xanthoxin→abscisic aldehyde→ABA transition as the last steps of the major ABA biosynthetic pathway.
Publisher
Oxford University Press (OUP)
Subject
Cell Biology,Plant Science
Reference53 articles.
1. Audran, C., Borel, C., Frey, A., Sotta, B., Meyer, C., Simonneau, T., and Marion-Poll, A. (1998). Expression studies of the zeaxanthin epoxidase gene in Nicotiana plumbaginifolia. Plant Physiol. 118 , 1021–1028. 2. Audran, C., Liotenberg, S., Gonneau, M., North, H., Frey, A., Tap-Waksman, K., Vartanian, N., and Marion-Poll, A. (2001). Localisation and expression of zeaxanthin epoxidase mRNA in Arabidopsis in response to drought stress and during seed development. Aust. J. Plant Physiol. 28 , 1161–1173. 3. Bell, C.J., and Ecker, J.R. (1994). Assignment of 30 microsatellite loci to the linkage map of Arabidopsis. Genomics 19 , 137–144. 4. Bewley, J.D. (1997). Seed germination and dormancy. Plant Cell 9 , 1055–1066. 5. Bittner, F., Oreb, M., and Mendel, R.R. (2001). ABA3 is a molybdenum cofactor sulfurase required for activation of aldehyde oxidase and xanthine dehydrogenase in Arabidopsis thaliana. J. Biol. Chem. 276 , 40381–40384.
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